171  
ACUS11 KWNS 302236  
SWOMCD  
SPC MCD 302235  
ORZ000-CAZ000-010030-  
 
MESOSCALE DISCUSSION 1528  
NWS STORM PREDICTION CENTER NORMAN OK  
0535 PM CDT MON JUN 30 2025  
 
AREAS AFFECTED...PORTIONS OF NORTHERN CA AND SOUTHERN OR  
 
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY  
 
VALID 302235Z - 010030Z  
 
PROBABILITY OF WATCH ISSUANCE...20 PERCENT  
 
SUMMARY...SCATTERED THUNDERSTORM DEVELOPING OVER THE HIGHER TERRAIN  
WILL GRADUALLY EXPAND IN COVERAGE/INTENSITY THIS EVENING. ISOLATED  
DAMAGING GUSTS AND SMALL HAIL ARE POSSIBLE WITH THE STRONGEST  
STORMS. A WW IS NOT ANTICIPATED, THOUGH CONVECTIVE TRENDS WILL  
CONTINUE TO BE MONITORED.  
 
DISCUSSION...AS OF 2230 UTC, REGIONAL SATELLITE AND RADAR IMAGERY  
SHOWED INITIAL THUNDERSTORMS HAVE INCREASED IN COVER/INTENSITY  
ACROSS PARTS OF NORTHERN CA AND SOUTHERN OR. MONSOON MOISTURE BEING  
ADVECTED AHEAD OF AN UPPER LOW OFF THE COAST OF CENTRAL CA HAS  
RESULTED IN ~1000 J/KG OF MUCAPE ATOP VERY STEEP LOW-LEVEL LAPSE  
RATES. THE WARM AND UNSTABLE AIR MASS WILL SUPPORT ADDITIONAL STORM  
DEVELOPMENT WITH CONTINUED ASCENT FROM A WEAK UPPER LOW, TYPICAL  
DIURNAL TERRAIN CIRCULATIONS. AS STORMS MATURE, SOUTHERLY DEEP-LAYER  
SHEAR AROUND 30 KT MAY ALLOW FOR SOME TRANSIENT ORGANIZATION IN THE  
FORM OF MULTICELL CLUSTERS OR WEAK SUPERCELLS. THE DRY SUB-CLOUD  
LAYER (DEEP MIXING TO NEAR 500 MB) WILL PROMOTE STRONG DOWNDRAFTS,  
CAPABLE OF ISOLATED SEVERE GUSTS. SOME SMALL HAIL WILL ALSO BE  
POSSIBLE WITH THE STRONGER CORES.  
 
SCATTERED STORMS WILL REMAIN POSSIBLE INTO THIS EVENING AND  
OVERNIGHT. GIVEN THE INCREASE IN CONVECTIVE COVERAGE AND THE GENERAL  
ENVIRONMENT, SOME SEVERE RISK COULD MATERIALIZE. HOWEVER, THE  
LIMITED POTENTIAL FOR STORM ORGANIZATION SUGGESTS A WW IS NOT  
LIKELY.  
 
..LYONS/BUNTING.. 06/30/2025  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...REV...MFR...STO...PQR...EKA...  
 
LAT...LON 41752378 43482322 43642211 42712013 41312017 41122067  
40622184 40502255 41752378  
 
MOST PROBABLE PEAK WIND GUST...55-70 MPH  
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  
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